Yep. That was EXACTLY the problem.

Our company is growing, and it was not me doing the whole install. Somebody else had opened and connected the DSS, and was not as paranoid as I was. He had just flipped a switch, got some kind of picture, and went home. I was only there basically to bless it when the customer brought it to my attention, and since I had not opened it and connected it, my memory was not jogged into thinking about the 720 vs. 108i issue. Somehow I even thought it only showed an image with the VGA connection when switched to 720. But noooooooooooooooooooooooooooo.........

So, several hours later, after even trying a component to VGA transcoder (where it worked because only 720 worked through the transcoder) I flipped the switch and fixed the problem.

Thanks for your other input, guys.

I do always carry a Xantech cable ground lifter with me. I did not think of that because it is orders of magnitude higher than 60 Hz. We (DirecTV, who fought me off for about an hour today) never could figure out what sort of artifact could make a signal of about 1000 Hz appear on the image like that.

And, of course, when I went there today, before solving the problem, it did not even appear on the screen when I got there.

I did not get around to disconnecting the cable signal, because both receivers worked on the other TV. In order to put a ground lifter on the plasma, I was about to call another guy and two mules to lift it down. This client wanted one of those "half inch on each side" mounts that can clip your fingers right down to size if you are not careful.

But all is well tonight.